The present invention relates to rotary gas locks utilized for transfer of coal into or ash out of an enclosed system, either pressure or vacuum, for which exchange of gases internal to the system with those external to the system is not desirable or permitted. The rotary gas lock is used as means for transferring the aforementioned material into of out of pressurized or vacuum system to minimize gas leakage. A toxic buffer gas may be used as a sealing barrier in this invention; if toxic gas is used as a sealing barrier, the toxic buffer gas will also be prevented from being released into the ambient atmosphere externally to the system. Prior art has disclosed the use of a rotary gas lock in conjunction with air, steam and other types of gases which are nontoxic and nonflammable and restrictive in pressure differential capabilities to a single rotary gas lock.
The general object of this invention is to transfer coal into, or ash out of pressurized processes having high temperature, flammable, toxic and contaminant-laden gases.
An object of the present invention is to eliminate the constraints associated with a single-stage rotary gas lock in a material transfer system.
Another object of this invention is to provide a new and novel arrangement of a multiple rotary gas lock and buffer-gas seal system for coal-feed or ash discharge into or out of a pressurized process, respectively.